\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx,bm}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide,ninecolors}
\usepackage{circuitikz}
\usepackage{amsmath}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes}
\ctikzset{bipoles/length=1cm}
\begin{document}
\small
\begin{circuitikz}[>=latex,yscale=1.0]
  % \draw(-1,-1.5)--(-0.5,-1.5);
  \draw(-2.5,-1.8)--(-2.6,-1.8)--(-2.6,0);
  \draw(0.7,-1.8)--(0.3,-1.8)--(0.3,0);
  \fill[top color=darkgray,bottom color=darkgray,middle color=white](3,-0.3)rectangle(-3,0.3);
  \draw(-0.6,-1.8)--(-0.5,-1.8)--(-0.5,-0.3)..controls(-0.5,0)and(-0.5,0.31)..(-0.7,0.31);
  \foreach \x in {-0.7,-1.0,...,-2.4}
  {
    \draw(\x,-0.31)..controls(\x-0.2,-0.31)and(\x-0.1,0.31)..(\x-0.3,0.31);
  }
  \draw(-1.6,-1.8) to[battery2](-2.6,-1.8);
  \draw(-1.6,-1.8) to[cute open switch=$K$](-0.6,-1.8);

  \draw(2.3,-1.8)--(2.4,-1.8)--(2.4,-0.3)..controls(2.4,0)and(2.4,0.31)..(2.2,0.31);
  \foreach \x in {0.7,1.0,...,2.4}
  {
    \draw(\x,-0.31)..controls(\x-0.2,-0.31)and(\x-0.1,0.31)..(\x-0.3,0.31);
  }
  \draw(0.3,-1.8) to[rmeter,name=dlj](2.4,-1.8);
  \draw[-stealth]([yshift=-2mm]dlj.center)--++(0,0.4)node[above=1mm]{$G$};
  \node at (-1.5,0.4)[above]{$M$};
  \node at (1.5,0.4)[above]{$P$};
\end{circuitikz}
\end{document}